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Dropping Crank For Rear Main Seal

Discussion in 'Early CJ-5 and CJ-6 Tech' started by Willys_Rubicon, Apr 7, 2019.

  1. Apr 7, 2019
    Willys_Rubicon

    Willys_Rubicon New Member

    Birmingham, AL
    Joined:
    Feb 15, 2019
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    Ok... this feels like an amateur question, but I have to ask it:

    I bought new neoprene seals for my 61 CJ5 after dealing with a continuous leak after driving. I took the oil pan off and the rear main cap and removed the original seals, which were neoprene to my surprise, so someone else has been in there I assume.

    No I am going in and trying to put in the top seal with crank in place, i can barely even get it started. I loosen all the mains and the crankshaft barely budged. I loosen all the rod caps too to see if those are holding them up. Nothing there either.

    All I can assume is that the flywheel and clutch is holding the crank in place? I assume I am going to need to take the transmission off to drop the crank to get that top seal in?

    Any pointers, I thought I could do this with crank in place like my old 4.0L I6 Jeep TJ, but apparently not. Seal was from KaiserWillys, I assumed it would be good quality .
     
  2. Apr 7, 2019
    iharding

    iharding Member

    Tacoma, WA
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    Feb 24, 2013
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    Push in the clutch?
     
  3. Apr 7, 2019
    65seejayfive

    65seejayfive Blazin’ new trails

    York, PA
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    Apr 10, 2018
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    Try having someone turn the crank as you push in to help “pull” the seal around. Oil the end of the seal as well before inserting.
     
  4. Apr 7, 2019
    Willys_Rubicon

    Willys_Rubicon New Member

    Birmingham, AL
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    Feb 15, 2019
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    Iharding, I actually tried this with no effect. Then it occured to me that the trans input shaft is in the pilot bearing so it probably wouldnt move anyway right?

    65cj5, working on getting some help to try this out too. Was attempting to do it one handed, but that was a failed attempt

    Thanks for the help so far guys, I appreciate it!
     
    iharding likes this.
  5. Apr 7, 2019
    iharding

    iharding Member

    Tacoma, WA
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    Feb 24, 2013
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    Ah. True. I tried this job but couldn’t even get the main cap bolts loose and gave up so don’t listen to me!
     
  6. Apr 7, 2019
    65seejayfive

    65seejayfive Blazin’ new trails

    York, PA
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    I definitely benefitted from a second set of hands! My seal was also front/back specific so I took special care to make sure I was sliding it in correctly. All I had to remove was the rear main cap. It was an awesome feeling seeing it slide up in place. Good luck! (y)
     
  7. Apr 8, 2019
    Rick Whitson

    Rick Whitson Detroit Area Sponsor 2019 Sponsor

    I live South of...
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    Wow didn't think of that, I put mine in on an engine stand it was easy, pulled the crank pully, and loosened the mains, piece of cake.
     
  8. Apr 8, 2019
    Willys_Rubicon

    Willys_Rubicon New Member

    Birmingham, AL
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    Feb 15, 2019
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    65Cj5, where did you get your seals from? I am starting to wonder if my KaiserWillys seals are too large. Very difficult to even get one started in the groove. I am certain I am putting it in correctly, it's just very tight in there.
     
  9. Apr 8, 2019
    70cj5134f

    70cj5134f Member

    East Tn
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    Aug 18, 2018
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    Put that seal in the freezer overnight, it will shrink a tad.
     
  10. Apr 8, 2019
    Willys_Rubicon

    Willys_Rubicon New Member

    Birmingham, AL
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    Hmmm good idea, I will give the freezer it a try! Thanks
     
  11. Apr 8, 2019
    65seejayfive

    65seejayfive Blazin’ new trails

    York, PA
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    I used this one from eBay and I have had very good luck. I’ve had this seal in place for almost a year and haven’t had one drip. I am very happy with mine. The seller says they are one of the best on the market and I believe him.

    https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/112320472680
     
  12. Apr 8, 2019
    Willys_Rubicon

    Willys_Rubicon New Member

    Birmingham, AL
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    This is the second time i have been referenced to this seal on ebay. Went ahead and ordered on based on your experience. Worth it to me fo try it out. Thanks!
     
  13. Apr 8, 2019
    Keys5a

    Keys5a Sponsor Sponsor

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    When you install the upper side of the seal, position it on the underside of the crank, and push the old top half out as the new one guides in. Leave about 1/4" offset at the block/main cap line.
    I've bought the seal on eBay from QTM/quarterton military and it was real nice quality-no leaks!
    -Donny
     
  14. Apr 8, 2019
    Greevesman

    Greevesman Sponsor Sponsor

    Napa, Ca
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    That looks like the one I used. I got it from Midwest Military. They also tell you not to "clock" the ends. Just leave them up equally on each side.
    I turned the crank while a friend fed the seal in. He got a lot of oil on him and was unhappy.
     
    adams77 and Bowbender like this.
  15. Apr 8, 2019
    Willys_Rubicon

    Willys_Rubicon New Member

    Birmingham, AL
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    Good to hear the success stories, my new seal will be here Friday, so I will be eager to try and get it in. Hopefully I just needed this better seal.
     
  16. Apr 8, 2019
    Bowbender

    Bowbender I'm workin' on it! Sponsor

    Northern Minn.
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    ….and a friend to feed it in while you turn the crank...:D
     
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  17. Apr 9, 2019
    Willys_Rubicon

    Willys_Rubicon New Member

    Birmingham, AL
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    That too! I have a buddy lined up to help
     
    Bowbender likes this.
  18. Apr 9, 2019
    Primer Coat

    Primer Coat New Member

    Ohio
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    Not sure what it is meant by don't "clock" the ends.
     
  19. Apr 9, 2019
    65seejayfive

    65seejayfive Blazin’ new trails

    York, PA
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    Got this picture from another thread (thanks Johns1967CJ5(y))
    The top half and the bottom half are turned 3/8-1/2” so they don’t line up straight across. That way the seam where they meet isn’t straight across. Hope this makes sense. BTW, I did not do this, my instructions said not to.
    [​IMG]
     
  20. Apr 9, 2019
    Primer Coat

    Primer Coat New Member

    Ohio
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    Thanks. I have seen this and it makes sense to me. I did not do it AND it leaks. Next time I'll do it this way.
     

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